Because it’s hopelessly impractical with today’s spaceships. Because we’d have to spin the tiny spaceships we have now really fast to get any useful force, but that would make steering the spaceship impossible (the main thrust comes from the bottom of a rocket but all the steering comes from smaller jets on the side of the rocket). Because that centrifugal force decreases from maximum at the surface of the hull to zero along the axis of rotation, so if you even moved your head from side to side, you’d experience extreme tidal forces that might ever make you black out. Because adding a mechanism to spin a rocket would add a huge amount of weight to the rocket and consume a lot of power. Because you’d have to spin it down any time you docker with anything at turn

If you ask the question, “Why haven’t scientists thought about X?” and you don’t have any science background yourself, 99.9% of the time the answer is, “Scientists have been thinking about X for generations.”

The first time I heard about the idea of spinning a vessel on outer space to get “artificial gravity” was in 1969, when I saw 2001, but the idea had been around for almost twenty years by then.

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